High tension apparatus



March 7, 1944. R. R. MAcHLETT HIGH TENSION APPARATUS Filed oet. 1e. 1942 the two sets of terminals in engagement.

Patented Mar. 7, 1944 HIGH TENSION APPARATUS Raymond R. Machlett, NevT Canaan, Conn., as-

signor to Machlett Laboratories Incorporated,

cut

New Canaan, Conn., a corporation of Connecti- Application (Pctober 16, 1942, Serial No. 462,268 i 8 Claims. (Cl. Z50-104) are avoided. At the same time, the parts may be readily put together and taken apart to establish or break the connection. As the new connection affords special advantages when used with X-ray tubes, an embodiment of the invention for use with such tubes will be illustrated and described in detail for purposes of explanation.

I The X-ray tube with which the new connection vis ,employed has an envelope with a re-entrant `end through which extend one or more leads lfrom one of the electrodes withinthe envelope.

A plate of insulation carrying terminals on its outer face lies Within the re-entrant end and the leads are `connected to the terminals. An insulator, of a size receivable in the refentrant end,

is mounted on the cable and it is provided with exposed terminals connected to the conductors in the cable and engageable with those on the plate. when the insulator is introduced intothe re-entrant end. -The end of the insulator is constructed to cooperate with the Wall of the envelope to enclose the terminals and means are provided for holding the insulator in place with With this arrangement, the cable may be connected to the element within the tube by inserting the insulator into the cavity in the lenvelope and .securing it in place by the holding means, and disconnection is effected with equal facility. LFora better understanding of the invention,

reference may be had to the accompanying drawing in which Fig. l isa view, partly in elevation and partly inlongitudinal section, of an X-ray unit and the new connection bywhich high tension en' ergy may be supplied to the tube thereof; and

- Fig. 2 is a similar view on an enlarged scale ,closed in tube generally designated IU which comprises .a glass'envelope II having a re-entrant end portion I2 at one end. Projecting inwardly from thisend is an extension I3 of the envelope wall in the end of which isseaued a metal tube la n vcarrying the cathode structure.

' The cathode includes a tube I5 telescoped over tube I4 and spot welded thereto. A metal .tocusing block I6 is mounted in the free end'of tube I5 and the block has a transverse channel Il in its Afree end. An incandescent lament vvI8 ofA helical form lies within the channel and 4is connected to leads I9 and 20. which extend through the block, lead I9 being insulated from the block by being mounted in blocks 2I and 22 of ceramic material. The leads I9 and 20 extend through and aresealed in the wall of the envelope at the bottom 'of the re-entrant cavity. A plate 23 of insulating material isseated near the bottom of the cavity and the leads pass through it to the outer surface. The space between the bottom of the cavity and the plate 23 is filled with insulating compound 24 through which portions of the leads pass. o

Mounted on the outer'face of plate23 is a -terminal 25 of cylindrical ,form and having a flange 25a lying against and secured to thevouter face of plate 23. Lead i9 passesl through an opening in therplate and/is electrically connected to the flange 25a,.` Amterminal 26. is `mounted in a central opening `through plate A23 `and lead 20 passes through theopening and into the interior of the terminaLmto which itis electrically connected. l

The tube envelope' is completed by a metallic .section 21 in the end-of which is mounted an Vanode 28. The tube is enclosed Within ahousing 29 having an end portion secured in .place on the shank of the anode inany suitableway. The opposite end of thehousing liesslightly beyond the end of theglass portion ofthe tube envelope and includes a ring 39 which is threaded externally. l l f A u y. n

The cable 3 Il by whichcurrent is to be supplied to the cathode includes lthe usual conductors eninsulation and the insulation. is stripped lback from the end of the cable and the conductors `are Vprovided lwith leadsl-32, 33. A

sleeve 34 of insulating material is nttedlqver vthe end of the cable and the sleeveis -closed Vat its free end vby a block 35 of insulating material lying inward from the endof theinjs'ulator.- and having openings through which leadsSZand 33 pass. The block is provided with an extension 35a on which is mounted a helical spring'terminal 36 connected to lead 372, the spring being of such diameter as to fit over the cylindrical portion of terminal 25 and bear against the flange 25a thereof. Threaded into a central bore through block 35 is a sleeve 31 which projects beyond the end of extension 35a and'carries a smaller helical spring terminal 38 which is connected to lead 33 and is of such diameter as to receive the terminal 26.

When the insulator is received in the re-entrant portion of the envelope and the contacts are engaged, the path through the space between the insulator and the envelope wall from the terminals to the nearest grounded portion of the apparatus is blocked off and the'terminals are shut oi from Contact with the atmosphere. For this purpose, the outer surface of insulator 34 is circumferentially channeled at its freeend and a cylindrical sleeve of yielding insulating material and preferably synthetic rubber of the type known as neoprene" is mounted in the channel. The sleeve 39 is of such length that when the insulator is inserted in the re-entrant portion of the envelope suiliciently to cause terminals 35 and 38 to engage terminals 25 and 2S, respectively, the free end of the sleeve presses against the outer face of plate 23, so that the terminals are completely enclosed. By shutting off the space surrounding the contacts from the atmosphere, corona is reduced and to inhibit corrosion resulting from corona, the terminals may be silver plated and the space within the insulator and sleeve 39 may be lled with insulating material, such as Vaseline At the outer end of the insulator is a metal ilare 40 connected to the metallic sheathing on the cable and thereby grounded. Beyond the flare is a clamping collar 4I serving as part of a means for holding the end of the cable with the insulator in the re-entrant portion of the tube and the terminals in contact. For this purpose, the flare is seated against a washer 42 which bears against the sleeve 30 on the housing. A clamping nut 43 mounted on the clamping ring and internally threaded may be screwed on section 30 of the tube housing to force the clamping ring, flare, and insulator inwardly and hold them securely in position.

By making terminals 25, 26, 36, and 38 of silver, corrosion arising from corona may be cut down to such an extent that sleeve 39 may be made of spun metal instead of synthetic rubber. The contact between the spun metal sleeve and plate 23 may permit some leakage of air, but with the terminals protected against-corrosion, such air leakage is not important, provided the path from the terminals to ground between the insulator and the wall of the envelope is sunlciently long. The spun metallic member radiates heat to the tube housing and it is preferred in some cases for that reason.

With the construction described, the re-entrant portion of the tube serves as 'an insulating socket for receiving the insulator enclosing the end of the cable, and since the terminals are at the bottom of the cavity, the distance between the terminals and any grounded portion of the structure may be made long without substantially increasing the overall length of the apparatus. II the insulator 34 were received in a socket mounted in the end of the housing and separate from the tube, the overall length of the housing would have to be greatly increased to make the socket long enough to- -provide a path of the desired length from the terminals to'ground.

In connecting the unit to a. source of energy, the insulator on the end of the cable is merely inserted through the end of housing 29 and into the cavity at the re-entrant end of the tube until the terminals are brought into contact. Thereafter, the clamping ring 43 is screwed tightly on the end of the housing and the parts are held in operative position. When the cable is to be disconnected, the clamping ring is unscrewed and insulator 34 pulled out of the end of the tube.

I claim:

1. In X-ray apparatus, the combination of a tube including an envelope having a re-entrant portion at one end, an anode within the tube at the other end having a portion extending through the envelope Wall, a cathode within the envelope, a terminal within the re-entrant end portion, a conductor sealed through the envelope wall and connected to said terminal and to the cathode lament, a housing enclosing the tube, a cable extending into the housing and having its end within the re-entrant end portion of the envelope, the cable containing at least one conductor, a terminal at the end of the cable connected to the conductor and in engagement with the rst terminal, cooperating means on the insulator and envelope at the inner end of the re-entrant portion of the envelope for shutting off the engaged terminals from the atmosphere, a grounded flare encircling and connected to the cable outside the re-entrant end portion of the envelope, and means mounted on the housing and engaging the envelope, and a member mounted on the housing and clamping the are to the housing to hold the end portion of the cable in the re-entrant end portion of the envelope with the terminals in engagement.

2. In high tension vacuum apparatus, the combination of an exhausted envelope having a reentrant portion, an element within the envelope, a terminal mounted within said re-entrant portion and connected through the envelope wall to said element, an insulated cable containing a conductor, an insulator enclosing the end of the cable, a terminal at the end of the insulator connected to the conductor, the insulator being insertable into the re-entrant portion of the envelope to eiect engagement of the terminals, and cooperating means on the insulator and envelope at the inner end of the re-entrant portion of the envelope for shutting off the engaged terminals from the atmosphere.

3. In high tension vacuum apparatus, the combination of an exhausted envelope having a reentrant portion, an element within the envelope, a terminal mounted within said re-entrant portion and connected through the envelope Wall to said element, an insulated cable containing a conductor, an insulator enclosing the end of the cable, a terminal at the end of the insulator connected to the conductor, the insulator being insertable into the re-entrant portion of the envelope to effect engagement of the terminals, and cooperating means on the insulator and envelope shutting off the terminals from the atmosphere when they are in engagement, said 'means including a tubular element projecting beyond the free end of the insulator and encircling the terminal thereon.

4. In high tension vacuum apparatus, the combination of an exhausted envelope having a reentrant portion, an element within the envelope, a terminal mounted within said re-entrant portion and connected through the envelope wall to said element, an insulated cable containing a conductor, an insulator enclosing the end of the cable, a terminal at the end of the insulator connected to the conductor, the insulator being insertable into the lre-entrant portion of the envelope to eiect engagement of the terminals, and cooperating means on the insulator and envelope shutting oi the terminals from the atmosphere when they are in engagement, said means including a tubular element of exible elastic insulating material projecting beyond the free end of the insulator and encircling the terminal thereon.

5. In high tension vacuum apparatus, the combination of an exhausted envelope having a reentrant portion, an element within the envelope, a plate of insulating material Within the reentrant portion, a terminal mounted on the outer side of the plate and connected through the envelope Wall to said element, an insulated cable containing a conductor, an insulator enclosing the end of the cable, a terminal at the end of the insulator connected to the conductor, the insulator being insertable into the re-entrant portion of the envelope to effect engagement of the terminals, and means on the insulator engageable With the plate, when the terminals are in contact, to shut off the terminals from the atmosphere.

6. In high tension vacuum apparatus, the combination of an exhausted envelope having a reentrant portion, an element Within the envelope, a plate of insulating material at the inner end of the re-entrant portion, a terminal mounted on the outer side of the plate and connected through the envelope Wall to said element, an insulated cable containing a conductor, an insulator enclosing the end of the cable, a terminal at the end of the insulator connected to the conductor, the insulator being insertable into the re-entrant portion of the envelope to eiect engagement of the terminals, and a tubular element on the insulator engageable with the plate, when the terminals are in contact, to shut off the terminals from the atmosphere.

7. In high tension vacuum apparatus, the combination of an exhausted envelope having a reentrant portion, an element within the envelope, a plate of insulating material Within the reentrant portion, a terminal mounted on the outer side of the plate and connected through the envelope Wall to said element, an insulated cable containing a conductor, an insulator enclosing the end of the cable, a terminal at the end of the insulator connected to the conductor, the insulator being insertable into the re-entrant portion of the envelope to effect engagement of the terminals, and a tubular element mounted on the insulator at its free end and projecting beyond said end, said element being engageable with the plate, when the terminals are in contact, to shut off the terminals from the atmosphere.

8. In X-ray apparatus, the combination of a tube including an envelope having a re-entrant portion at one end, an anode and a cathode within the envelope, a terminal within the re-` entrant end portion, a conductor sealed through the envelope Wall and connected to said terminal and to the filament of the cathode, a housing enclosing the tube, an insulating cable containing a conductor, an insulator enclosing the end of the cable, a terminal at the free end of the insulator connected to the conductor` within the cable, the insulator being insertable into the reentrant portion of the envelope to effect engagement of the terminals, cooperating means on the insulator and envelope at the inner end of the re-entrant portion of the envelope for shutting off the engaged terminals from the atmosphere, a grounded metallic flare encircling and connected to the cable at the other end of the insulator, and a clamping member on the housing operable on the flare for holding the insulator in the reentrant end portion of the envelope with the terminals in engagement.

RAYMOND R. MACHLETT. 

